Measuring color using color filter arrays

ABSTRACT

Embodiments including color filter arrays are disclosed.

INTRODUCTION

Color measurement instruments can be broadly classified as colorimeters,abridged spectrometers, and spectrometers. Apparatuses that measurereflected light are called photometers, e.g., spectrophotometer, whereasapparatuses that measure emitted light are called radiometers, e.g.,spectroradiometer.

Some color measuring apparatuses have been proposed that can measureboth reflective and emissive objects. However, such apparatuses have tobe switched via user input in order to select between reflective andemissive measurements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a portable color measuring apparatus embodiment ofthe present disclosure.

FIG. 2A illustrates a color calibration component for use with aportable color measuring apparatus of the present disclosure.

FIG. 2B illustrates another color calibration component for use with aportable color measuring apparatus of the present disclosure.

FIG. 3 illustrates a representation of a color filter array having anumber filters formed with materials having different colorcharacteristics according to an embodiment of the present disclosure.

FIG. 4A illustrates a monitor attachment component for use with aportable color measuring apparatus of the present disclosure.

FIG. 4B illustrates another monitor attachment component for use with aportable color measuring apparatus of the present disclosure.

FIG. 4C illustrates a view of the monitor attachment component of FIG.4B taken along line 4C-4C.

FIG. 5A illustrates a representation of a set of example lighttransmission curves for an eight color filter array.

FIG. 5B illustrates representation of another set of example lighttransmission curves for an eight color filter array.

FIG. 6 illustrates a representation of light sources emitting light withdiffering intensities across a visible color spectrum according to anembodiment of the present disclosure.

FIG. 7 is a block diagram illustrating a method of measuring coloraccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure include systems, apparatuses, andmethods for providing abridged spectrophotometers and/orspectroradiometers. For example, in some embodiments through use of alarger number of color channels, e.g., greater than about 6 or 8, it ispossible to reconstruct or estimate the original spectral content of ameasured color for reflective objects. The present disclosure includesembodiments that describe the use of CFA's with 5 or more color channelsto create such apparatuses.

In general, spectrometers are more color accurate than abridgedspectrometers which are in turn more color accurate than colorimeters.This is often due to a decreasing number of color channels asapparatuses proceed from full spectrometers to calorimeters.

The number of color channels can be associated with sampling theory. Themore color channels, the finer the sampling of a light spectrumassociated with a particular color.

Colorimeters may have 34 color channels, abridged spectrometers may have5-16 channels whereas spectrometers may have 17 or more channels. Thenumber of channels associated with a particular classification ofinstrument is somewhat flexible, particularly between abridged and fullspectrometers.

Typically, the signal associated with a color channel arises from thecollection of light energy from a range of continuous wavelengths. Forexample, the light energy passing through a color filter that transmitswavelengths from a range such as 380-500 nm onto an electronic sensorthat generates a signal, can be called the ‘Blue’ channel signal. Tocreate a color channel, light has to be separated into multiple rangesof wavelengths.

Most instruments are based on a small set of light-separationtechnologies. These technologies include: (1) diffraction gratings; (2)interference filters; (3) color filter arrays; and (4) Light EmittingDiode (LED) based designs.

Technologies 1-3 separate light into ranges of wavelengths which thenfalls on multiple sensors to generate a simultaneous set of signals.LED-based designs use a monochromatic sensor and a series of differentcolored LED's which are turned on one-at-a-time to generate a sequenceof signals. Color filter arrays (CFA's) have used 3-4 color channelswhich are found in calorimeters.

The visible spectrum can be defined as light with wavelengthsapproximately between 400-700 nm. For example, the wavelength range of380-730 nm, can be considered the visible spectrum for manyapplications, which constitutes a range of 350 nm (i.e., 730 nm minus380 nm).

Some color capture apparatuses that have been proposed, such as somedigital cameras, use 3 filters to separate the incoming visible lightinto 3 channels of color information. Most digital cameras that useon-chip Color Filter Arrays (CFA) have RGB (red, green, and blue)transmissive color filters, while some use CMY filters (cyan, magenta,and yellow). Such filters have transmission curves which are relativelybroadband having widths of about 150 nm or so (e.g., usually a littlelarger than 350/3≈117).

When using these filters, the spectrum of a particular color passesthrough the filters and onto a number of sensors which create signalsproportional to the total light energy passing through each filter. Forexample, if a blue (B) filter allows light from 380-560 nm to betransmitted to the sensor beyond the filter, the total light energytransmitted through the filter is integrated by the sensor to produce asingle B signal or value. The same is true for the R and G filters.Consequently, the spectrum of any impinging color produces 3 channels ofcolor information, 3 signals associated with the R, G, and B filters.

Unfortunately, in such systems, it is possible for two colors withdifferent spectra to produce the same RGB values. This phenomenon isoften referred to as instrument metamerism (e.g., multiple colorsproducing the same instrument reading).

This is possible for the B channel, for example, since the light spectrain the 380-560 nm range may be different on a wavelength-by-wavelengthbasis, but may integrate across the B wavelength range to generate thesame B value at the sensor. For instance, color X might have more lightenergy at 423 nm while color Y might have more energy at 516 nm.

However, if the total light energy transmitted through the B filter tothe B sensor is the same, the B values will be the same and, hence,indistinguishable from the standpoint of the B signal. If this is truefor the R and G signal, as well, then RGB_(A)=RGB_(B). Consequently,color A and color B can be indistinguishable to the instrument eventhough the two colors may appear very different to the human observer.

One way to reduce instrument metamerism and/or improve color accuracy ingeneral is to use more than 3 channels of color information. In general,more color channels can result in higher color accuracy, in manysystems.

Highly accurate instruments might be obtained using 35 or even 70channels whereas less accurate instruments might be obtained using 6-12.However, the law of diminishing returns is generally at work in suchimplementations. That is, 70 channels may not be twice as accurate as 35channels.

For certain color measurement work, 6-12 channels can be used to produceacceptable color accuracy. Such additional channels of color informationcan be created with additional filters (e.g., 8 color channels can beaccomplished by 8 color filters).

There are several methods of creating additional filters. For example,with on-chip CFA's, existing RGBCMY filters may be combined in severalways.

Labor and material costs can be reduced by combining materials withdifferent color transmittance characteristics. For example, as describedbelow, combining a material used in a filter having a blue (B)transmittance intensity peak with a material used in a filter having amagenta (M) transmittance intensity peak can result in a color filterhaving a transmittance wavelength peak intensity different from either aB or M color filter.

As such, a combined B-M color filter, for example, can be used inaddition to, or instead of, another color filter to contribute toforming a color filter array (CFA). A C-M filter might be combined bymixing C and M colorants together before on-chip deposition or bystacking C and M filters on top of each other, one after the other.

Accordingly, among various embodiments of the present disclosure, acolor measuring apparatus can detect a color spectrum of an object usinga number of color filters, where a number of materials each having adifferent color spectral characteristic are used to form an array ofcolor filters transiting at least five portions of the color spectrum.The color measuring apparatus can utilize at least one color filter thatis a combination of at least two of the number of materials having adifferent color spectral characteristic.

In some embodiments, a color measuring apparatus can include, a colorfilter array having a number of filters thereon, where the number offilters transit light to a number of sensors of a sensing circuit in aportable color measuring apparatus. The apparatus can include one ormore memory locations having a number of sets of instructions executableby a processing circuit.

The memory can include instructions, for example, to select initiationof one or more sets of instructions for reflective color measuring and aset of instructions for emissive color measuring. In such embodiments,the one of the sets of reflective color measuring and emissive colormeasuring instructions utilize a number of specialized components thatis not utilized by the other set of instructions. In such embodiments,it may be that some components are utilized by both sets, but one ormore components (such as a light source) are not.

The memory can also include a number of other types of instructions. Forexample, the memory can include instructions to determine whether ameasurement is to be taken utilizing the reflective or emissive colormeasuring instructions based upon data from the color sensor itself orone or more additional sensors.

In some embodiments, the memory can include instructions to determinewhether sensor data taken from one or more sensors is reflective oremissive color data. The memory can include instructions to determinewhether sensor data was taken utilizing reflective or emissive colormeasuring instructions.

The memory can include instructions to take a first measurement with aninternal illuminant in an ON state, and to switch the illuminant to anOFF state to take a second measurement. In some embodiments, theapparatus can include an operator interface where an operator may selectthe first or second measurement.

Such selection can also be accomplished via executable instructions inmemory provided in software or firmware. Instructions can also beprovided to indicate to the operator a type of measurement that one ormore of the first or second measurements is.

In some embodiments, the apparatus can include an orientation sensor andinstructions to interpret orientation sensor data to determine whether atarget is emissive or reflective. In such embodiments, the apparatus caninclude an orientation sensor and instructions to interpret orientationsensor data to determine a type of measurement that is to be performedby the apparatus.

The present disclosure also includes a number of system embodiments, forexample, in some embodiments a portable color measuring system caninclude a color filter array having a number of filters thereon, wherethe number of filters transit light to a number of sensors of a sensingcircuit in a portable color measuring apparatus, a sensing means forsensing whether a target to be measured is a reflective or emissivelight source, and a processing circuit for processing instructions. Theinstructions to be processed can, for example, include instructions tointerpret data from the sensing mechanism and select initiation of a setof instructions for reflective color measuring or a set of instructionsfor emissive color measuring based upon the interpretation of the data.In such embodiments, the system can include one of the sets ofreflective color measuring or emissive color measuring instructionsutilizing a number of specialized components (e.g., a light-emittingdiode) that is not utilized by the other set of instructions.

In some embodiments, the specialized components utilized by thereflective color measuring instructions can include multiple lightsources (e.g., light-emitting diodes) each having different colorcharacteristics. In some such embodiments, the combination of emittedlight from the multiple light sources substantially covers a visiblecolor spectrum.

Some embodiments can be designed to with components that can facilitatecommunicating to a remote location using a wireless connection. Suchcomponents can include one or more transmitters, transceivers, and/orantennas, among other items. System embodiments can also include one ormore of the following components which provide additional functionalityto the system. Such functions and components include a mechanism torecord the light color spectrum measurement and/or the informationassociated with the object being measured on a storage medium that isremovable, a spot locator, a strip guide, a cathode ray tube holder, aliquid crystal display holder, and/or at least one calibration referencesample, where a group of calibration reference samples includes a whitesample, a black sample, and/or a gray sample.

The present disclosure also includes a number of method embodiments. Forexample, in some embodiments, the method can include detecting a colorspectrum of an object using a number of color filters.

In such embodiments, a number of materials each having a different colorspectral characteristic can be used to form an array of color filterstransiting at least five portions of the color spectrum. Embodiments canalso include selecting initiation of one or more sets of instructionsfor reflective color measuring and a set of instructions for emissivecolor measuring that each utilize at least one color filter that is acombination of at least two of the number of materials.

In some embodiments, the method can include taking a measurement withthe internal illuminant in an off state and analyzing the measurement todetermine if there is an amount of light energy over a threshold amount.Embodiments can also include taking a first measurement with theinternal illuminant in a first state, taking a second measurement withthe internal illuminant in a second state, and analyzing the first andsecond measurements to determine if there is a difference betweenamounts of light energy of the first and second measurements that isover a threshold amount. For example, the first state can be an offstate and the second state can be an on state, or in some embodiments,the first state can be a high state and the second state can be a lowstate.

In some embodiments, if the analysis of the first and secondmeasurements to determine if there is a difference between amounts oflight energy of the first and second measurements that is over athreshold amount indicates that the difference is over the threshold,then a target can be determined to be reflective. Accordingly, in someembodiments, if the analysis of the first and second measurements todetermine if there is a difference between amounts of light energy ofthe first and second measurements that is over a threshold amountindicates that the difference is not over the threshold, then a targetcan be determined to be emissive. Other such threshold baseddeterminations can be made based upon the sensor data and/orcalculations thereof, such as the difference.

FIG. 1 illustrates an example portable color measuring apparatussuitable to implement embodiments of the present disclosure. Theembodiment of the portable color measuring apparatus 120 shown in FIG. 1can be used for measuring intensities of portions of a color spectrum oflight reflected by an object and/or light emitted by an object.

As such, as will be appreciated by one of ordinary skill in the relevantart, the portable color measuring apparatus 120 can function as aspectrophotometer by measuring color reflected from an object and/orfunction as a spectroradiometer by measuring color emitted by theobject. In some embodiments, the color measuring apparatus can bedesigned to determine the type of light to be analyzed(reflected/emitted) and can, therefore, switch between two mechanismsfor measuring the light. This switching functionality can beaccomplished automatically, in some embodiments, such as through use ofexecutable instructions, and/or can be done through operator input.

To provide color measuring functionality, embodiments of the presentdisclosure include executable instructions stored in memory andexecutable by a processing circuit. For example, in the embodiment ofFIG. 1, the apparatus 120 includes a processor 101 and memory 103. Theprocessing circuit (e.g., processor) can be any suitable type ofprocessing circuitry and the memory can be any suitable type of fixed orremovable memory and memory is to be interpreted as includinginstructions stored in the form of firmware or software.

The memory can include instructions, for example, to select initiationof one or more sets of instructions for reflective color measuringand/or a set of instructions for emissive color measuring. In suchembodiments, the one of the sets of reflective color measuring andemissive color measuring instructions utilize a number of specializedcomponents that is not utilized by the other set of instructions. Insuch embodiments, it may be that some components are utilized by bothsets, but one or more components (such as a light source) are not.

The memory can also include a number of other types of instructions. Forexample, the memory can include instructions to determine whether ameasurement is to be taken utilizing the reflective or emissive colormeasuring instructions based upon data from one or more sensors.

In some embodiments, the memory can include instructions to determinewhether sensor data taken from one or more sensors (e.g., sensor 106) isreflective or emissive color data. The memory can include instructionsto determine whether sensor data was taken utilizing reflective oremissive color measuring instructions.

The memory can include instructions to take a first measurement with aninternal illuminant in an on state, and to switch the illuminant to anoff state to take a second measurement. In some embodiments, theapparatus can include an operator interface where an operator may selectthe first or second measurement.

Such selection can also be accomplished via executable instructions inmemory provided by software or firmware. Instructions can also beprovided to indicate to the operator a type of measurement that one ormore of the first or second measurements is.

The color measuring apparatus embodiment 120 of FIG. 1 can include acolor imaging functionality that can, for example, measure colorintensities in an image to be reproduced. In some embodiments, colormeasuring apparatuses, such as apparatus 120, can use a color measuringcomponent that implements CFA sensors as described below, among othersensor types.

In some embodiments, the color intensity values measured by the CFAsensors can be stored for image reproduction at a time determined by auser. By way of example and not by way of limitation, color measuringapparatus embodiments that utilize embodiments of color measuringcomponents of the present disclosure can be used with color imagingapparatuses which include, for example, printers (e.g., inkjet, laser,etc.), scanners, facsimile (fax) machines, and/or digital cameras, amongothers.

For instance, by way of example and not by way of limitation, a portablecolor measuring apparatus can be used for measuring a color gamut oflight being emitted while displaying an image on a display (e.g., acolor monitor connected to a computing apparatus and/or a highdefinition digital television screen). Such sensing apparatusembodiments also can, for example, be used for measuring colors ofreflected light associated with art work displayed in a museum,measuring light associated with an object of nature, and/or recordingcolor images of the previously mentioned objects, for example, throughimplementation in a digital camera.

The embodiment of the portable color measuring apparatus 120 shown inFIG. 1 includes a housing 122 that can house or be associated with someor all of the elements described in embodiments of the presentdisclosure. The housing can include a number of buttons, switches,and/or other user input mechanisms that can be used to provide operatorinterface functionality. For example, the housing of the portable colormeasuring apparatus 120 can include a menu button and an escape buttonto provide an operator interface for control over (e.g.,selection/deletion) information and/or functions shown in a displaywindow 127.

An operator interface of the present disclosure can, among other uses,be used to control an application software package can being utilizedand/or to enter information associated with an object being measured.For example, an operator interface can include a display window that canhave one or more functions. For example, a display window can allow theuser to access the light color spectrum measurement in real time.

In some embodiments, a display window can allow access to theinformation associated with the object being measured as the informationis being entered. Additionally, a display window can allow access to astored light color spectrum measurement and/or stored informationassociated with a measured object.

In some embodiments, a display window can present a menu(s) (e.g., in amultilevel format) that allows a user access to functions and/orinformation accessible to the portable color measuring apparatus.Presentation of the functions and/or information to the user in adisplay window can, in some embodiments, be performed using a digitalgraphics display (e.g., LCD). In some embodiments, the display windowcan be a touch screen that can allow a user to input commands orselections by touch the screen with their finger or a stylus, forexample.

In some embodiments, the apparatus may be capable of automaticallydetecting whether or not a reflective or emissive measurement is beingmade and turn on or turn off an illumination source autonomously. Oneway this can be accomplished is by taking a reading with and without theinternal illuminant turned on and determining the nature of the signalbased upon the difference in the readings.

Another way to accomplish this can be to automatically determine theorientation of the apparatus. For instance, spectrophotometricmeasurements are usually made with the reflective media lying flat(e.g., printer profiling) whereas spectroradiometric measurements aretypically made with the emissive media vertical (e.g., computer monitorprofiling).

One or more sensors can be used to provide an indication of theorientation of the apparatus. For instance an orientation sensor, suchas a gravity sensor, magnetic sensor, or the like, can be used todetermine whether the apparatus is oriented generally vertically orhorizontally.

In various embodiments, the housing 122 of the portable color measuringapparatus 120 shown in FIG. 1 can include a number of buttons 128 toprovide a user interface for selection of various items or to providefunctionality to the user interface. For example, the buttons can beused to select from a number of various programs that, when executed,can, for example, control measurement of color in an object beingexamined.

For instance, some embodiments can be designed such that an operatorcould input a selection of a type of measurement to be made (e.g.,reflective or emissive). A mechanism is described below to provide theportable color measuring apparatus 120 with the various programs fromwhich choices can be made through the user interface.

As shown in FIG. 1, the housing 122 of the portable color measuringapparatus 120 can be configured, in various embodiments, to include alight input aperture 130. The light input aperture 130 can allow lightreflected from and/or emitted by an object being measured to directly orindirectly reach at least one CFA associated with sensors and circuitryenabling measurement of intensities of portions of a color spectrum ofinterest to a user as described in embodiments of the presentdisclosure. The light input aperture can be of any suitable type and/orshape.

In some embodiments, as illustrated in FIG. 1, the housing 122 can beconfigured to include one or more light output components. The lightoutput component can allow a light source (e.g., a light-emitting diode)134 to illuminate an object to facilitate measurement of intensities ofportions of a color spectrum of interest to a user by enhancingavailable light to be reflected from the object being measured.

As described below, various types and numbers of light sources can beutilized individually and/or in combination to illuminate the objectbeing measured with light having characteristics (e.g., a particularspectral range of wavelengths, a particular intensity of wavelengths ina portion of a spectral range, etc.) of interest to a user. The portablecolor measuring system can include, in some embodiments, alight-emitting diode for illumination of an object to be measured. Invarious embodiments, such as described below, a system can include atleast two light-emitting diodes each having different colorcharacteristics, where a combination of emitted light substantiallycovers a visible color spectrum.

The light input aperture and the light output component are illustratedin FIG. 1 as being positioned proximate to each other on one end of theapparatus 120, however, the placement of the light input aperture 130and the light output component 134 can be configured, in variousarrangements. Additionally, a light input aperture for CFA sensors and alight output aperture for a light source can be separable from a singlehousing or included in separate housings.

In some embodiments, the portable color measuring apparatus 120illustrated in FIG. 1 can be utilized as a component of a system forconveying information to a remote location (e.g., using a wiredconnection, a wireless connection, a removable information storagemedium, and/or other ways of conveying information to a remote location)related to intensities of portions of a color spectrum detected by theportable color measuring apparatus 120. At the remote location, thesensed light information can, for example, be used by processingcircuitry to enable execution of functions by an associated systemapparatus (e.g., a personal computer, a printer, etc).

In various embodiments, the portable color measuring apparatus caninclude a mechanism for communicating an intensity of light sensed bythe sensing circuit to a remote location. The mechanism forcommunicating to the remote location can include a wireless connectionand/or a wired connection, for example, as described below.

In such embodiments, the housing 122 of the portable color measuringapparatus 120 can, for example, include a structure for an antenna 138that can provide wireless communication with a component of the systemat the remote location. In some embodiments one or more transmittersand/or transceivers can be used. The placement of the antenna 138 on theportable color measuring apparatus 120 is chosen for ease ofillustration and not by way of limitation.

Accordingly, the portable color measuring system can include, in variousembodiments, a processing circuit at the remote location forinterpreting an intensity of a sensed portion of a light color spectrumas a measurement thereof. Measurements of the sensed portion of thelight color spectrum can be stored in association with informationrelated to a measured object.

A portable color measuring system can include a CFA 100 having a numberof filters thereon, where the number of filters transit light to anumber of sensors of a sensing circuit in a portable color measuringapparatus. In the embodiment of FIG. 1, a CFA 100 includes circuitry 102(e.g., a circuit board) that can be connected to a processing circuit.The circuitry 102 of the CFA 100 embodiment can be associated with anumber of sensors (e.g., photodiodes) that can enable registering of anintensity of light being sensed.

By way of example and not by way of limitation, each sensor of the CFA100 can be associated with at least one color filter 106. Although onlyone CFA, one circuit, and one filter are illustrated in FIG. 1, variousembodiments can include multiple CFAs, circuits, and/or color filters.

The embodiment of the portable color measuring apparatus 120 illustratedin FIG. 1 includes a power source component 140. The power sourcecomponent 140 can house a supply of electrical energy that enablesoperation of various electrically powered functions in the portablecolor measuring apparatus 120 when the apparatus is unconnected toanother source of electrical energy (e.g., an alternating current walloutlet). By way of example and not by way of limitation, the powersource component 140 can house various types of power sources (e.g., oneor more disposable/replaceable batteries, rechargeable batteries, manualinduction coils, and/or fuel cells, among other types).

As illustrated in the embodiment of the portable color measuringapparatus 120 shown in FIG. 1, the apparatus can include a power switchbutton or other user actuatable mechanism. In some embodiments, thedevice can include a proximity sensor and can power up when positionedwithin proximity to an object to be targeted. In the embodiment of FIG.1, the power switch 146 can, for example, control whether electricallypowered functions in and/or associated with the housing 122 can besupplied with electrical energy by the power source component 140.

As shown in FIG. 1, in some embodiments, the portable color measuringapparatus 120 can include a connector 147. The connector 147 can, invarious embodiments, enable the portable color measuring apparatus 120to communicate with outside processing circuitry (e.g., at a remotelocation) using a wired connection. The connector 147 can serve as anelectrical energy input to enable operation of the portable colormeasuring apparatus 120 and/or to enable recharging of a rechargeablepower source component 140.

In some embodiments, wireless and/or wired connection of the portablecolor measuring apparatus 120 to a remote location can be accomplishedthrough use of a docking station (not shown) that can allow a savedintensity of the light sensed by a sensing circuit to be communicated tothe remote location, where the connector 147 can serve to link theportable color measuring apparatus 120 to the docking station. A dockingstation can, in some embodiments, enable input through the connector 147of information and/or executable instructions obtained from the remotelocation through wireless communication or otherwise.

In some embodiments of the present disclosure, a portable colormeasuring apparatus can include its own processing circuit forinterpreting the intensity of a sensed portion of the light colorspectrum as a measurement thereof. A portable color measuring apparatuscan include internal memory storage for the light color spectrummeasurement and/or information associated with the object beingmeasured. In some embodiments, a portable color measuring apparatus caninclude a mechanism to calibrate its processing circuit (e.g., by usinga calibration reference sample).

As illustrated in the embodiment of the portable color measuringapparatus 120 shown in FIG. 1, the apparatus can include an input port148 that, among other functions, can receive a storage medium 150 (e.g.,a flash memory card) on which additional embodiments of executableinstructions are stored (e.g., an application software package(s) forinterpreting intensities of sensed portions of a color spectrum asmeasurements thereof). Instructions that can be provided to the portablesensing apparatus can include, for example, instructions for executingcolor matching, match prediction, batch correction, tinting strengthcalculations, shade sorting, and other functions.

In various embodiments, the input port 148 shown in FIG. 1 can be usedwith the portable color measuring apparatus 120 to enable recording alight color spectrum measurement and/or information associated with anobject being measured on a storage medium (e.g., a flash memory card)that can be inserted and removed from the input port 148. Recordinginformation on a storage medium and/or accessing information recorded ona storage medium can be performed by a portable color measuringapparatus using various techniques.

In various embodiments of the portable color measuring apparatus 120shown in FIG. 1, the apparatus can include an integral spot locator, astrip guide, a cathode ray tube (CRT) holder, and/or a liquid crystaldisplay (LCD) holder. In some embodiments, the portable color measuringapparatus 120 can include at least one calibration reference sample,where a group of calibration reference samples includes a white sample,a black sample, and/or a gray sample. In various embodiments, thecalibration reference sample(s) can be positioned inside and/or outsidethe housing of the portable color measuring apparatus for calibrationthereof.

FIG. 2A illustrates a color calibration component for use with aportable color measuring apparatus of the present disclosure. Colorcalibration components can be provided in various forms and can beprovided on the device or off of the device. Although two on devicemechanisms are illustrated herein in FIGS. 2A and 2B, other alternativemechanisms can be utilized within the scope of one or more embodimentsof the present disclosure.

In the embodiment of FIG. 2A, the calibration mechanism is an end cap260. The end cap can be mounted on the end of the device (e.g., end thatincludes light source 134 and light input 130 in the embodiment of FIG.1). In such an embodiment, a white reference, or other reference type,can be provided on the end cap. In such embodiments, when the lightsource shines on the white reference, the device can be calibrated to aknown reference and, therefore, can take more accurate colormeasurements, in some instances.

FIG. 2B illustrates another color calibration component for use with aportable color measuring apparatus of the present disclosure. In theembodiment of FIG. 2B, the mechanism is an end cap 260 having a mirror268 for directing light from a light source toward one of a number ofreference components (e.g., references 265, 266, and 267 of FIG. 2B). Analternate embodiment would be to rotate the light source (not shown) andsensor 269 instead of the mirror 268.

In the embodiment of FIG. 2B, the reference 265 is a white reference,the reference 266 is a reflectance aperture, and the reference 267 is aradiometric aperture. In some embodiments, the mirror 268 can be fixedand the reference and apertures 265, 266, and 267 can be moved (e.g.,rotated) to align each with the mirror 268. Additionally, in someembodiments, the mirror 268 can move (e.g., rotate) and the referenceand apertures 265, 266, and 267 can be fixed.

In some such embodiments, the end cap can be designed such that theaperture opens and closes (e.g., by rotation of one or more end capcomponents). In this way, a reference (e.g., a white reference) can beprovided within the end cap and can be used while the one or moreapertures are open and/or closed. Such an arrangement can allow forvarious different calibrations to be taken.

Detecting which aperture or reference is selected can be used todetermine the type of color measurement is to be taken. For example, insome embodiments, the type of calibration selected or being made can beused to indicate to the device what type of measurement is to be takenand the device can switch, for example from reflective to emissive basedupon the orientation of the endcap.

FIG. 3 illustrates a representation of a color filter array having anumber filters formed with materials having different colorcharacteristics according to an embodiment of the present disclosure.FIG. 3 illustrates a representation of an embodiment of a CFA 300 thatincludes an arrangement of eight (8) different color filters each havinga different color spectrum transiting characteristic that are used toform an array of color filters.

The CFA 300 shown in FIG. 3 can represent various types of CFAs. Assuch, the number of filter colors shown, the placement of the filtercolors in the array, and the proportion of one color filter to anothercolor filter are illustrated by way of example and not by way oflimitation. For example, the CFA 300 has two (2) rows of color filtersand four (4) columns of color filters, thereby yielding a total of eight(8) color filters. However, CFAs of the present disclosure can includefive or more color filters positioned in any configuration for detectinga color spectrum of an object.

Embodiments of the present disclosure include a number of materials eachhaving a different color spectral characteristic that, for example, canbe used to form an array of color filters transiting at least fiveportions of the color spectrum. For example, five materials each havinga different color spectral characteristic can be used to form fivedifferent color filters that transit portions of a color spectrum havingfive different peak intensities.

In some embodiments of the present disclosure, a fifth given colorfilter can be formed using a combination of two or more materials thatincludes a combination of materials at least one of which is not used inany of the other color filters. Moreover, in various embodiments, one ormore of the color filters that can be used in an array of color filterstransiting at least five portions of the color spectrum can be formedusing a combination of at least two materials each having a differentcolor spectral characteristic.

In the embodiment of the CFA 300 shown in FIG. 3, the array of colorfilters can be positioned in association with circuitry 302 for sensingan intensity of a portion of the color spectrum transiting eachassociated color filter. Some embodiments of CFA 300, by way of exampleand not by way of limitation, can include a first row 304 that includesa number of color filters 305-1, 305-2, 305-3, . . . 305-N that can usea number of materials each having a different color spectralcharacteristic to form different color filters that transit portions ofa color spectrum having different peak intensities.

The embodiment of the CFA 300 can include a second row 307 that includesa number of color filters 308-1, 308-2, . . . 308-N that, in someembodiments, can use a number of materials each having a different colorspectral characteristic to form different color filters that transitportions of a color spectrum having different peak intensities. In someembodiments, each of the examples of color filters (i.e., 305-1, 305-2,305-3, . . . 305-N) in the first row 304 can use materials having acolor spectral characteristic that is different from color spectralcharacteristics of each of the example color filters (308-1, 308-2, . .. 308-N) in the second row 307.

As illustrated in the embodiment of CFA 300 shown in FIG. 3, by way ofexample and not by way of limitation, the second row 307 of the CFA 300can include a color filter 310 that is a combination of at least two ofthe number of materials, as described above. The CFA 300 can representvarious embodiments of CFAs that can be included in various embodimentsof color measuring apparatuses where each of the at least two materialscan have a different color spectral characteristic.

Such CFA embodiments can include a number of sensing circuits forsensing light transiting at least one of the filters, where each of thefilters is associated with at least one sensing circuit. The CFAs can befurther associated with a processing circuit to interpret the colorspectral characteristics of the sensed light as at least five colorchannels, where the number of filters used can enable the colormeasuring apparatus to measure the color channels as spaced in a colorspectrum.

FIGS. 4A-4C illustrates mechanisms for switching the device between areflective and an emissive measuring configuration. For example, FIG. 4Aillustrates a monitor attachment component for use with a portable colormeasuring apparatus of the present disclosure. In the embodiment of FIG.4A, the device includes an arm 433 and a button 435.

In such an embodiment, the arm 433, can be used to mount the deviceagainst an emissive item to be measured, such as a monitor (not shown)or the like, such that the end of the device having the light source 434and the light input 430 are proximate to (e.g., near or against) thesurface of the emissive item to be measured. For example, the arm 433can be designed as a hanger or mounting bracket among other mechanismsfor positioning the device near the item to be measured.

When the arm 433 is extended, the button 435 is actuated and theactuation indicates that the device is to be used for measuring anemissive item. One of ordinary skill in the art will understand thatthere a various other orientations of components can type of mechanismsthat can be used to indicate that the device is to be placed inproximity to an emissive item to take a measurement and to switch themode of the device between emissive and reflective functionality.

FIG. 4B illustrates another monitor attachment component for use with aportable color measuring apparatus of the present disclosure. In theembodiment of FIG. 4B, the device housing 422 is mounted to a hanger 425having an emissive item mount 423 and a device mount 426.

This mechanism is similar to that of FIG. 4A in that the coupling of thedevice housing 422 with the hanger 425 can be utilized to signal theswitching of the device between emissive and reflective measurementfunctionality. In some embodiments, this switching can be automatic toenable the device to be more quickly and effectively utilized.

FIG. 4C illustrates a view of the monitor attachment component of FIG.4B taken along line 4C-4C. In the embodiment of FIGS. 4B and 4C, thesignaling of the coupling can be provided by the coupling of hangers 426with apertures 429 (e.g., shown here provided around the end of thedevice housing the light source 434 and light input 430 of the devicehousing 422). For example, a sensor can be positioned to sense thecoupling of the device mounts 426 with the apertures 429 in the housing422. The information from the sensor can be used to switch thefunctionality of the device.

FIG. 5A illustrates a representation of a set of example lighttransmission curves for an eight color filter array. The graphillustrated in FIG. 5A shows a representation of relative intensity oflight transmittance through various embodiments of color filters on thevertical axis within a spectrum of light wavelengths measured innanometers (nm) on the horizontal axis.

Each transmission curve can be referred to by the wavelength value ofits peak or maximum transmittance value. Each transmission curve alsohas an associated width. The width can be determined by the wavelengthswhere the transmittance values fall to some predetermined level (e.g.,where the transmittance is 50% of the peak transmittance or falls below10% without regard to the peak transmittance). For example, if a filterhas its peak transmittance value at a wavelength equal to 550 nm and thetransmittance falls to 0.1 at wavelengths of 530 nm and 580 nm, thefilter can be referred to as the ‘550 nm’ or green filter with a 0.1bandwidth of 50 nm (580-530 nm).

In the 0.0 to 1.0 scale on the vertical axis of the graph, a low valuecan indicate relatively little transmittance of a particular colorwavelength through a particular color filter, whereas a value closer to1.0 can indicate relatively higher transmittance of a particular colorwavelength through a particular color filter. The wavelength spectrumshown on the horizontal axis of the graph can represent a color spectrumvisible to the human eye, which can range from around 380 nm througharound 730 nm.

In the graph, transmittance intensity curves for eight color filters areshown as measured across the visible color spectrum. The eight colorfilters were formed using one or more sets of materials with differingcolor spectral characteristics. As discussed above, this could also beaccomplished by changing the thickness of the same type of material,thereby creating different color spectral characteristics.

Combination of at least two colors such as two or more selected from R1(a material having a first set of red color characteristics), G1, B1, R2(a material having a second set of red color characteristics), G2, B2and/or other materials having different color spectrum characteristics,can result in forming a color filter that transits a peak intensity of awavelength that can differ from peak wavelengths transited by colorfilters such as those that are identified as transiting B1 (520-1), B2(520-2), G1 (520-3), G2 (520-4), R1 (520-5, and R2 (520-N). In someembodiments, combining at least two materials identified with formingcolor filters, such as two or more selected from R1, G1, B1, R2, G2, B2,can assist in forming a CFA that transits peak intensities ofwavelengths spaced across a visible color spectrum.

As illustrated in the graph of FIG. 5A, a number of curves are shown520-1, 520-2, 520-3, 520-4, 520-5 . . . 520-N that, by way of exampleand not by way of limitation, demonstrate transmittance profiles ofeight different color filters formed using sets of materials thattransit R1, G1, B1, R2, G2, B2 peak color intensities when usedindividually.

Achieving particular ratios of materials contributing to particularcolors can be performed by, in some embodiments, using two layers of Bcolor filters to one layer of G color filter, for example, or by, insome embodiments, mixing double the concentration of a material used ina B color filter with a concentration regularly used in a G colorfilter, for example. Using thicker layers of color filters and/orincreased concentrations of materials for one color relative to anothercolor can, in some embodiments, result in a peak intensity wavelength tobe shifted relative to those achieved using the individual materialsand/or equal combinations of the two. As discussed above and asillustrated in the graph of FIG. 5A, in some embodiments, greater orlesser concentrations of a color can be used.

For instance, increasing the thickness of a color filter, and/orincreasing the concentration of materials used to form the color filter,can, in some embodiments, result in decreasing the intensity of lighttransited by the color filter, including the peak transmittancewavelength. Such peak intensity differences can, in some embodiments, becompensated for using processing circuitry, if it is not useful.

As illustrated by the graph in FIG. 5A, a number of materials eachhaving a different color spectral characteristic can be used to form anarray of color filters transiting at least five portions of a visiblecolor spectrum. Various combinations of color filters thus formed canprovide a peak intensity of light within one of the portions of thecolor spectrum to the circuitry for sensing.

In various embodiments, appropriate combinations of materials can enableselecting color filters such that the peaks of the portions can bespaced at substantially regular intervals across the visible colorspectrum. Using various embodiments described in the present disclosure,a color measuring apparatus can have color channel spacing that can bedetermined by spacing of a peak intensity of light transiting eachfilter associated with each channel through a number of sensingcircuits. In some embodiments, the overlap of the color channels can beused to more specifically identify a color sensed by using informationcollected via more than one of the color channels. In this manner, thecombination of color channel information can provide more accurateinformation and can reduce or eliminate metamerism.

FIG. 5B illustrates representation of another set of example lighttransmission curves for an eight color filter array. As with the graphof FIG. 5A, the graph illustrated in FIG. 5B illustrates arepresentation of relative intensity of light transmittance throughvarious embodiments of color filters on the vertical axis within aspectrum of light wavelengths measured in nanometers (nm) on thehorizontal axis.

In this representation, each transmission curve can be referred to bythe wavelength value of its peak or maximum transmittance value. Eachtransmission curve also has an associated width.

As with the representation of FIG. 5A, the width can be determined bythe wavelengths where the transmittance values fall to somepredetermined level (e.g., where the transmittance is 50% of the peaktransmittance or falls below 10% without regard to the peaktransmittance). For example, if a filter has its peak transmittancevalue at a wavelength equal to 550 nm and the transmittance falls to 0.1at wavelengths of 530 nm and 580 nm, the filter can be referred to asthe ‘550 nm’ or green filter with a 0.1 bandwidth of 50 nm (580-530 nm).

As in the representation of FIG. 5A, in the 0.0 to 1.0 scale on thevertical axis of the graph, a low value can indicate relatively littletransmittance of a particular color wavelength through a particularcolor filter, whereas a value closer to 1.0 can indicate relativelyhigher transmittance of a particular color wavelength through aparticular color filter. The wavelength spectrum shown on the horizontalaxis of the graph can represent a color spectrum visible to the humaneye, which can range from around 380 nm through around 730 nm.

Graphs, such as those shown in FIGS. 5A and 5B, can be used to determinea particular wavelength at which a color filter allows a peaktransmittance intensity and its associated bandwidth. By measuring thetransmittance of more than one color filter, a determination can be madeof a separation distance(s) between the wavelengths of the peaktransmittance intensities.

In the graph of FIG. 5B, transmittance intensity curves for eight colorfilters are shown as measured across the visible color spectrum. Theeight color filters were formed using one or more sets of materials withdiffering color spectral characteristics.

In the representation of FIG. 5B, the intensities of the filters arealso changed across the spectrum. This can be an added factor that canbe used to better identify a color being measured. The changes in theposition of the filters across the spectrum, their widths as representedon the graph, and their intensities could be accomplished by changingthe thickness of the same type of material, thereby creating differentcolor spectral characteristics, or by using different combinations ofone or more materials, having the same or different thicknesses and/ordensities.

For example, as discussed above with respect to the representation ofFIG. 5A, achieving particular ratios of materials contributing toparticular colors can be performed by, in some embodiments, using twolayers of B color filters to one layer of G color filter, for example,or by, in some embodiments, mixing double the concentration of amaterial used in a B color filter with a concentration regularly used ina G color filter, for example. Using thicker layers of color filtersand/or increased concentrations of materials for one color relative toanother color can, in some embodiments, result in a peak intensitywavelength to be shifted relative to those achieved using the individualmaterials and/or equal combinations of the two.

As illustrated by the graph in FIG. 5B, a number of materials eachhaving a different color spectral characteristic and one or moredifferent intensities can be used to form an array of color filterstransiting at least five portions of a visible color spectrum. Variouscombinations of color filters thus formed can provide a peak intensityof light within one of the portions of the color spectrum to thecircuitry for sensing.

FIG. 6 illustrates a representation of light sources emitting light withdiffering intensities across a visible color spectrum according to anembodiment of the present disclosure. Suitable light sources can, forexample, be gas discharge, incandescent, or LED-based, among others. Theselection can be based upon a number of factors. For example, LED's areconvenient since they can be easier to drive, less expensive, and/orcooler, than the above mentioned gas discharge and incandescentexamples.

Embodiments of the present disclosure can utilize a number of lightsources having different light emitting characteristics. In providingsuch light sources, the apparatus can be applied in a number ofsituations. For example, the apparatus can be designed with suitablelight sources to provide color accuracy, measurement according toindustry standards, measurement of special materials, among otherfunctions.

The graph 600 illustrated in FIG. 6 shows a representation of relativeintensity of light emitted by various embodiments of light-emittingdiodes (LEDs), and combinations thereof, on the vertical axis within aspectrum of light wavelengths measured in nm on the horizontal axis.

In the 0.0 to 1.0 scale on the vertical axis of graph 600, a low valuecan indicate relatively little emission of a particular color wavelengthby a particular LED, or a particular combination of LEDs, whereas avalue closer to 1.0 can indicate relatively higher emission of aparticular color wavelength by a particular LED, or a particularcombination of LEDs. The wavelength spectrum shown on the horizontalaxis of graph 600 can represent a color spectrum visible to the humaneye, which can range from around 380 nm through around 730 nm.

A graph such as that shown in FIG. 6 can be used to determine particularwavelengths at which a particular LED, a particular combination of LEDs,and/or other light sources, emit one or more peaks and valleys ofintensity at wavelengths throughout a color spectrum, along withrelative emission intensities in between. In graph 600, emissionintensity curves for five particular LEDs, or particular combinations ofLEDs, are shown as measured across the visible color spectrum.

As further described below, a particular LED that emits light in adefined wavelength range can be combined with a particular phosphor(s)that can be excited by the light emitted by the LED and can emit lighthaving a range of longer light wavelengths to broaden the color spectrumof the light emitted by the LED light source. The five LED light sourcesshown in graph 600 were formed using a number of individual LEDs with aspecific phosphor(s), or combinations thereof.

Illuminating an object to enable potential reflection of lightwavelengths ranging across a visible color spectrum, and therebyenabling adequate measurement of the object's colors, can be achievedusing light sources that emit high intensity of light, with relativeuniformity of intensity, across the spectrum to be measured, forexample, from around 380 nm through around 730 nm, in some embodiments.Some spectrophotometers can use a light source such as a tungsten lampor xenon flash that can provide a broad range of illumination. However,such apparatuses are often expensive. A less expensivespectrophotometer, or a calorimeter, can use a “white light LED”, asdescribed below, among other light sources.

The graph 600 illustrated in FIG. 6 shows a range of light emissionintensities that can be produced by an embodiment of a “white light”LED. A white light LED can include a LED that emits blue lightwavelengths combined with a yellow phosphor that can become excited bythe blue light wavelengths to emit a range of longer wavelengths oflight.

A curve 620 illustrating intensities of light in a visible spectrum thatcan be produced by an embodiment of a white light LED is shown in graph600. The curve 620 shows that a white light LED can emit light havinghigh intensity (around 1.0) in a blue region of the color spectrum withmore moderate intensities (from around 0.2 to around 0.4) up to theorange-red region of the color spectrum.

Notably, as shown in the curve 620 of graph 600, the white light LEDembodiment can emit an intensity that drops from around 0.1 to around0.0 at wavelengths shorter than around 430 nm. Because the human visualsystem (HVS) can perceive light wavelengths as short as 360-380 nm,illumination of an object with a white light LED that does not emitwavelengths that short, for reflection by the object, can introduceerror in color measurements made by a color measurement apparatus.

Complying with an applicable color imaging standard (e.g., an ISOProofing Standard) can include illuminating an object with a lightsource that substantially covers the color spectrum perceivable by theHVS. A high-brightness print medium can have “brighteners” to enhancethe intensity of reflected blue light. Among possible influences onprinted colors, a brightener can increase brightness so that a printmedium appears whiter than it would otherwise appear. Suchhigh-brightness print medium can utilize short wavelength light toexcite the brighteners. The ISO Proofing Standard specifies thatbrighteners are to be excited, which can be done with light sources thatemit wavelengths in the 380-420 nm range.

As illustrated in graph 600 of FIG. 6, curve 624 shows that anembodiment of an “ultra-blue” LED can emit light with a peak wavelengtharound 430 nm. The embodiment of the ultra-blue LED used for curve 624can emit light at around 420 nm with an intensity of around 0.2, whichis notably higher than the intensity emitted by the white light LED at420 nm shown in curve 620.

To improve accuracy of color measurement and better comply withapplicable imaging standards (e.g., the ISO Proofing Standard), a lightsource can be used for illuminating an object to be measured thatincludes an array of at least two LEDs each having different colorcharacteristics, where a combination of emitted light substantiallycovers a visible color spectrum. For example, graph 600 of FIG. 6illustrates an embodiment of combining the ultra-blue LED with the whitelight LED by showing the light emission curve 624 of the ultra-blue LEDmerging with the light emission curve 620 of the white light LED.

To more strongly excite brighteners in a print medium (e.g., to complywith the ISO Proofing Standard), a light source can be used havinghigher intensity emissions in wavelengths closer to 380 nm. For example,graph 600 of FIG. 6 illustrates an emission curve 628 for an embodimentof a “super-white” LED.

The embodiment of the super-white LED illustrated in graph 600 can beformed, for example, using a violet LED combined with three phosphors.The curve 628 for the super-white LED shows an emission intensity havinga broad peak (around 0.3) from around 390-400 nm. In some embodiments,combining the super-white LED with the ultra-blue LED and/or the whitelight LED can provide relative uniformity in the shorter wavelengths ofthe visible spectrum.

However, as shown in curve 628, at longer wavelengths (e.g., around615-630 nm and around 700 nm) the super-white LED embodiment can havenotable spikes in emission intensity. Hence, in some embodiments,accuracy of color measurement can decrease when using a super-white LED.Consequently, having an ability to selectively turn off and on a firsttype of a LED used in combination with a second type of a LED can beadvantageous.

Graph 600 of FIG. 6 illustrates an emission curve 632 for a firstembodiment of a “warm-white” LED. The warm-white LED can be formed usinga blue LED combined with a particular combination of yellow and redphosphors. The curve 632 for the warm-white LED shows an emissionintensity reaching a peak (at around 1.0) at a wavelength around 560-570nm in the green portion of the color spectrum.

From the peak, the curve 632 shows intensities that decline gradually aswavelengths reach the red and far-red portions of the color spectrum(e.g., the intensity reaches around 0.2 at around 705 nm). In someembodiments, combining the warm-white LED with the super-white LED, theultra-blue LED, and/or the white light LED can provide increasedintensity and/or relative uniformity in the longer wavelengths of thevisible spectrum.

Graph 600 of FIG. 6 illustrates an emission curve 636 for a secondembodiment of a “warm-white” LED. The second embodiment of thewarm-white LED can be formed using a blue LED combined with a particularcombination of yellow and red phosphors that differ from the phosphorsused in the first embodiment of the warm-white LED.

The curve 636 for the warm-white LED shows an emission intensityreaching a peak (at around 1.0) at a wavelength around 630-640 nm in thered portion of the color spectrum. From the peak, the curve 636 showsintensities that decline more sharply than the 632 curve as wavelengthsreach the far-red portion of the color spectrum (e.g., where theintensity also reaches around 0.2 at around 705 nm).

In some embodiments, combining the second embodiment of the warm-whiteLED with the first embodiment of the warm-white LED, the super-whiteLED, the ultra-blue LED, and/or the white light LED can provideincreased intensity and/or relative uniformity in the longer wavelengthsof the visible spectrum. Hence, an illumination system for a colormeasuring apparatus can include a number of embodiments of LEDs and/orother light sources, each of which can be turned on and offindependently, or in programmed combinations, to improve colormeasurement and/or to comply with a particular imaging standard and/orto match interests of a particular user.

FIG. 7 is a block diagram illustrating a method of measuring coloraccording to an embodiment of the present disclosure. Unless explicitlystated, the method embodiments described herein are not constrained to aparticular order or sequence. Additionally, some of the described methodembodiments, or elements thereof, can occur or be performed at the same,or at least substantially the same, point in time.

The embodiments described herein can be performed using logic, software,hardware, application modules, or combinations of these elements, andthe like, to perform the operations described herein. Embodiments asdescribed herein are not limited to any particular operating environmentor to software written in a particular programming language. In variousembodiments, the elements just described can be resident on the systems,and/or apparatuses shown herein, or otherwise.

Logic suitable for performing embodiments of the present disclosure canbe resident in one or more apparatuses and/or locations. Processingmodules used to execute operations described herein can include one ormore individual modules that perform a plurality of functions, separatemodules connected together, and/or independent modules.

The embodiment illustrated in FIG. 7 includes a method of measuringcolor, including permitting light to enter into the device, at block790. In such embodiments, the light can be either refelective oremissive light.

The method embodiment of FIG. 7 also includes separating multiple lightinduced spectral subranges from the light, at block 792. In block 793,the method includes taking a measurement of the separated spectralsubranges with a sensor by selecting initation of one or more sets ofinstructions from a set of instructions for reflective color measuringand a set of instructions for emissive color measuring.

The method of FIG. 7 includes analyzing one or more sensor signals fromthe sensor, at block 794. The method also includes outputting a measuredcolor determination based upon the analysis of the one or more sensorsignals, at block 795.

In some embodiments, a method can include taking a measurement with theinternal illuminant in an off state and analyzing the measurement todetermine if there is an amount of light energy over a threshold amount.Embodiments can also include taking a first measurement with theinternal illuminant in a first state, taking a second measurement withthe internal illuminant in a second state, and analyzing the first andsecond measurements to determine if there is a difference betweenamounts of light energy of the first and second measurements that isover a threshold amount. For example, the first state can be an offstate and the second state can be an on state, or in some embodiments,the first state can be a high state and the second state can be a lowstate.

In some embodiments, if the analysis of the first and secondmeasurements to determine if there is a difference between amounts oflight energy of the first and second measurements that is over athreshold amount indicates that the difference is over the threshold,then a target can be determined to be reflective. Accordingly, in someembodiments, if the analysis of the first and second measurements todetermine if there is a difference between amounts of light energy ofthe first and second measurements that is over a threshold amountindicates that the difference is not over the threshold, then a targetcan be determined to be emissive. Other such threshold baseddeterminations can be made based upon the sensor data and/orcalculations thereof, such as the difference.

Although specific embodiments have been illustrated and describedherein, those of ordinary skill in the art will appreciate that anarrangement calculated to achieve the same techniques can be substitutedfor the specific embodiments shown. This disclosure is intended to coverall adaptations or variations of various embodiments of the presentdisclosure.

It is to be understood that the above description has been made in anillustrative fashion, and not a restrictive one. Combination of theabove embodiments, and other embodiments not specifically describedherein will be apparent to those of skill in the art upon reviewing theabove description.

The scope of the various embodiments of the present disclosure includesother applications in which the above structures and methods are used.Therefore, the scope of various embodiments of the present disclosureshould be determined with reference to the appended claims, along withthe full range of equivalents to which such claims are entitled.

In the foregoing Detailed Description, various features are groupedtogether in a single embodiment for the purpose of streamlining thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the disclosed embodiments of the presentdisclosure have to use more features than are expressly recited in eachclaim.

Rather, as the following claims reflect, inventive subject matter liesin less than all features of a single disclosed embodiment. Thus, thefollowing claims are hereby incorporated into the Detailed Description,with each claim standing on its own as a separate embodiment.

1. A color measuring apparatus, comprising: a color filter array havinga number of filters thereon, where the number of filters transit lightto a number of sensors of a sensing circuit in a portable colormeasuring apparatus; a memory having a number of sets of instructionsexecutable by a processing circuit; and the memory includinginstructions to: select initiation of one or more sets of instructionsfor reflective color measuring and a set of instructions for emissivecolor measuring; and where one of the sets of reflective color measuringand emissive color measuring instructions utilize a number ofspecialized components that is not utilized by the other set ofinstructions.
 2. The color measuring apparatus of claim 1, where thememory includes instructions to determine whether a measurement is to betaken utilizing the reflective or emissive color measuring instructionsbased upon data from one or more sensors.
 3. The color measuringapparatus of claim 1, where the memory includes instructions todetermine whether sensor data taken from one or more sensors isreflective or emissive color data.
 4. The color measuring apparatus ofclaim 1, where the memory includes instructions to determine whethersensor data was taken utilizing the reflective or emissive colormeasuring instructions.
 5. The color measuring apparatus of claim 1,where the memory includes instructions to take a first measurement withan internal illuminant in an on state, and to switch the illuminant toan off state to take a second measurement.
 6. The color measuringapparatus of claim 5, where the apparatus includes an operator interfacewhere an operator may select the first or second measurement.
 7. Thecolor measuring apparatus of claim 5, where the apparatus includes a setof instructions to indicate to the operator a type of measurement thatone or more of the first or second measurements is.
 8. The colormeasuring apparatus of claim 5, where the apparatus includes anorientation sensor and instructions to interpret orientation sensor datato determine whether a target is emissive or reflective.
 9. The colormeasuring apparatus of claim 1, where the apparatus includes anorientation sensor and instructions to interpret orientation sensor datato determine a type of measurement that is to be performed by theapparatus.
 10. A portable color measuring system, comprising: a colorfilter array having a number of filters thereon, where the number offilters transit light to a number of sensors of a sensing circuit in aportable color measuring apparatus; a sensing means for sensing whethera target to be measured is a reflective or emissive light source; and aprocessing circuit for processing instructions to: interpret data fromthe sensing mechanism; select initiation of a set of instructions forreflective color measuring or a set of instructions for emissive colormeasuring based upon the interpretation of the data; and where one ofthe sets of reflective color measuring or emissive color measuringinstructions utilize a number of specialized components that is notutilized by the other set of instructions.
 11. The system of claim 10,where the specialized components utilized by the reflective colormeasuring instructions includes a light-emitting diode for illuminationof an object to be measured.
 12. The system of claim 11, where thespecialized components utilized by the reflective color measuringinstructions includes at least two light-emitting diodes each havingdifferent color characteristics, where a combination of emitted lightsubstantially covers a visible color spectrum.
 13. The system of claim10, where the system includes means of communicating to a remotelocation using a wireless connection.
 14. The system of claim 10, wherethe portable color measuring apparatus includes: a means to record thelight color spectrum measurement and the information associated with theobject being measured on a storage medium that is removable; a spotlocator; a strip guide; a cathode ray tube holder; a liquid crystaldisplay holder; and at least one calibration reference sample, where agroup of calibration reference samples includes a white sample, a blacksample, and a gray sample.
 15. The system of claim 10, where theportable color measuring apparatus includes a color calibrationcomponent.
 16. The system of claim 10, where the portable colormeasuring apparatus includes a color calibration component havingmultiple reference components.
 17. A method of measuring color,comprising: permitting light to enter into the device; separatingmultiple light induced spectral subranges from the light; taking ameasurement of the separated spectral subranges with a sensor byselecting initiation of one or more sets of instructions from a set ofinstructions for reflective color measuring and a set of instructionsfor emissive color measuring; analyzing one or more sensor signals fromthe sensor; and outputting a measured color determination based upon theanalysis of the one or more sensor signals.
 18. The method of claim 17,where taking a measurement includes taking a measurement with theinternal illuminant in an off state; and where analyzing one or moresensor signals from the sensor includes analyzing the measurement todetermine if there is an amount of light energy over a threshold amount.19. The method of claim 17, where taking a measurement includes taking afirst measurement with the internal illuminant in a first state; takinga second measurement with the internal illuminant in a second state; andwhere analyzing one or more sensor signals from the sensor includesanalyzing the first and second measurements to determine if there is adifference between amounts of light energy of the first and secondmeasurements that is over a threshold amount.
 20. The method of claim19, where the first state is an off state and the second state is an onstate.
 21. The method of claim 19, where the first state is a high stateand the second state is a low state.
 22. The method of claim 19, whereif the analysis of the first and second measurements to determine ifthere is a difference between amounts of light energy of the first andsecond measurements that is over a threshold amount indicates that thedifference is over the threshold, then a target is determined to bereflective.